Can anyone tell me how thick is too thick for panelization to be used. We have a board current that is 100 mils thick and I was told it can not be panelized. Could anyone tell me if this is true or not.

V-score - .100" is probably to thick for manual seperation. There are machines that I believe can cut through a V-Score up to .125" or greater

Breakaway tabs - .100" is getting to the limit when doing this manually. However there are "nibblers" that take care of a thick board for depaneling.

PCB router - no problem.

If using the breakaways, you need to make sure that there is no circuitry within .100" of tabs. These will sometimes cause a little damage at the break area. V-Score seperation also requires a "keepout" distance that is dependent on the type and model of machine used.

So the answer is yes you can panelize a .100" board. the other question is Can your assembly house get it apart?